Morton’s neuroma occurs when thickened tissue forms around nerves at the ball of the foot, causing foot pain with every step. Some of the symptoms overlap with those of multiple sclerosis (MS), which can lead the conditions to be mistaken for the other. It’s also possible to have both Morton’s neuroma and MS, which could make it harder to receive an accurate diagnosis.

“Has anyone been diagnosed with Morton’s neuroma?” one member of MyMSTeam asked. “I was wondering if it’s connected with MS.” If you’re also wondering about this connection, here’s what you need to know about Morton’s neuroma and MS.

Symptoms of Morton’s Neuroma and MS

Morton’s neuroma develops when a nerve — usually the one between the third and fourth toes — becomes irritated, causing it to thicken. You may feel like you’re always standing or walking on a small rock, even after you empty your shoes and check for other problems. You may also experience numbness in the affected toes or a tingling feeling like pins and needles. Along with these common symptoms, some people feel a burning pain that radiates from the ball of the foot through the forefoot toward the toes.

Some symptoms of Morton’s neuroma, particularly numbness and tingling, can overlap with those of MS. Neuropathic pain (nerve pain), which affects up to one-quarter of people with MS, results from MS-related damage to the myelin sheath — a protective coating around the nerves in the brain and spinal cord. This process, called demyelination, interferes with the nerves’ ability to send signals to the brain and leads to sensations of burning, stabbing, pins and needles, or squeezing.

If someone already diagnosed with MS develops those symptoms, the sensations may be mistakenly attributed to MS alone, and Morton’s neuroma could be missed entirely.

The Relationship Between Morton’s Neuroma and MS

Morton’s neuroma and MS aren’t believed to be directly related. MS isn’t a risk factor for Morton’s neuroma and vice versa. They’re two different conditions that can occur together and have some similar symptoms.

Morton’s neuroma is more common in women than in men, according to the American Academy of Orthopaedic Surgeons, and tends to be diagnosed in middle age. These risk factors are similar to those of MS.

Morton’s Neuroma and Autoimmune Diseases

It’s important to note that, unlike MS, Morton’s neuroma is not an autoimmune disease, meaning it doesn’t involve the body attacking its own healthy tissues. Instead, Morton’s neuroma is believed to result from nerves in the foot being compressed, or squeezed. However, Morton’s neuroma can occur alongside other autoimmune diseases. For example, 40 percent of people with Morton’s neuroma also have rheumatoid arthritis.

Foot Pain and MS

Morton’s neuroma may also worsen foot-related symptoms of MS, such as neuropathic pain. People with MS can experience foot drop. This condition occurs when ankle weakness makes it hard to position your foot correctly while walking.

It’s also common for people with MS to develop other foot problems, such as plantar fasciitis, an injury to the ligament in the arch. Another issue, claw toes (a condition in which the last two toe joints bend into a clawlike shape), can contribute to foot pain and is common among people with MS. Walking difficulties may also arise due to nerve damage, balance problems, spasticity (feelings of stiffness and muscle spasms), fatigue, muscle weakness, and more.

Pain from Morton’s neuroma could make MS pain worse. In addition, Morton’s neuroma may go undiagnosed in people with MS because they assume their discomfort stems from MS.

Causes and Risk Factors of Morton’s Neuroma

Morton’s neuroma usually results from pressure on the affected nerve, but other sources of irritation or injury could also cause the condition. For example, high-impact sports and activities such as running put consistent pressure on the balls of the feet. Wearing tight shoes, like those designed for cycling or rock climbing, or high heels can also lead to the condition. Morton’s neuroma can also result from a foot deformity such as a bunion, hammertoe, flatfeet, or high arches.

Diagnosis of Morton’s Neuroma With MS

Doctors can’t look at your feet and see that you have Morton’s neuroma. Instead, they may perform a clinical examination and various tests, such as Mulder’s click test — flexing your feet and listening for clicks that indicate Morton’s neuroma. They may also gently squeeze the space between your toes to see if it causes pain, another sign.

Your doctor may want to confirm the diagnosis with an imaging test. Both ultrasound and MRI can effectively diagnose Morton’s neuroma, and some doctors may also do X-rays. These tests can eliminate other causes of foot pain, such as stress fractures.

If you have MS, it may be harder to determine if foot pain is from Morton’s neuroma or related to MS. Imaging often helps resolve any confusion quickly because the neuroma can be seen on the test. The location of your pain may also be key. MS can cause pain throughout the foot, but pain from Morton’s neuroma is usually concentrated in the ball of your foot.

Treatment of Morton’s Neuroma

Therapies for Morton’s neuroma include both surgical and nonsurgical treatment options. Be sure that any doctor prescribing drugs for Morton’s neuroma or another condition knows that you also have MS. This will help them choose medications that you can safely take with your MS treatments. They may try a more conservative approach first to minimize complications.

Change Your Footwear

Treating Morton’s neuroma often starts with the right footwear. Make sure your shoes are wide enough across the ball of the foot. They also should have about a half inch of space between your toes and the shoe tip (toe box). If you need special permission to wear such shoes at work, your doctor can help you explain your medical condition.

You may need to add custom orthotics or inserts to your shoes and commit to wearing them regularly, at least for a while. The inserts will remove pressure from the neuroma so it can heal. If they don’t seem to be helping, follow up with your doctor.

Rest and Ice

Take the pressure off the neuroma by resting your foot. Stay off your feet as much as possible, and avoid exercise or physical strain that may make pain worse. Minimize weight bearing as much as possible.

While resting, put an ice pack either over or under your toes (wherever it seems most effective). Applying ice for 15 minutes at a time can help reduce swelling and inflammation in the soft tissue around the neuroma.

Steroid Injections

Although other, more experimental injectable treatments may help with Morton’s neuroma, the most common injections involve corticosteroids. Your health care team will work with you to determine whether you can try corticosteroid injections and how to avoid interfering with your MS treatments.

Surgery

Surgery for Morton’s neuroma is usually performed only after other treatments fail or if the condition is severe. Various surgical procedures can remove a neuroma, and your doctor will choose an approach based on the location, size, and other details of your neuroma.

Sometimes, doctors may try to remove pressure from the nerves in the foot without removing the neuroma. Another option involves performing surgery to treat another condition (like hammertoe), with the aim of relieving pressure that led to the neuroma.

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Are you living with Morton’s neuroma and MS? How has it affected your quality of life? Share your story in the comments below or by posting on your Activities page.